stra-ngways



2 SheetsSheet 1.

(No Model.)

H. B. T. STRANGWAYS.

TELEPHONE.

Patented Apr. 22, 18.84

(No Model.) 2 SheetsSheet 2.

H. 'B. T. STRANGWAYS.

TELEPHONE- No. 297,470. Patented Apr. 22, 1884;

wire STATES ATENT FFlCE HENRY B. T. STRANGWVAYS, OF LONDON, ENGLAND.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 297,470, dated April 22, 1884.

Application filed November 22, 1882.

To all whom it may concern:

Be it known that I, BULL TEMPLER STRANG-WAYS, barrister at law, of Pump Court, Temple, in the city of London, England, have invented a new and useful Improvement in Telephones. of which the following is aspeciiication.

My invention is applicable to telephones, whether used as transmitters or receivers, and relates to telephones in which a small magnet or short bar of metal capable of inductive action is attached to the center of the diaphragm or other vibrator in line with another magnet or piece of metal, both said magnets being surrounded by helices through which the current is passed.

My invention consists in the combinat-ion,in

an electric telephone, with the diaphragm orother vibrator fitted with a small magnet or piece of metal capable of inductive act-ion, and a main magnet opposed to said small magnet, of coils or helices arranged concentric with the two said magnets, and wound so that a divided current will flow through each of the coils or helices in one and the same direction, and act simultaneously and in precise] y the same manner upon the two magnets.

The result of the combination above de scribed is to increase the electric effect of the action of the diaphragm or vibrator, and consequently the strength of the current produced in and transmitted by the instrument, and to increase the electrical effect of the varying currents upon the receiver, and consequently the volume of sound produced.

In the accompanying drawings, Figure 1 is a longitudinal section of a telephone-receiver of the ordinary type arranged to suit the purposes of my invention. Fig. 2 is asimilar section of a telephone-receiver, in which is used a horseshoe or two-legged magnet instead of a straight bar-magnet, and which also embodies my invention; and Fig. 3 is a diagram illustrating one manner of winding the helices.

Similar letters of reference designate corresponding parts in all the figures.

Referring first to Fig. 1, A designates the telephone-case, within the handle of which is fixed a permanent bar-magnet, 13, having, as usual,a coil or helix, 0, of insulated wire,wound around a bobbin, 0, 011 its upper end, .or that (No model.)

end which is nearest the diaphragm D. To this diaphragm, which may be made of wood or metal or any other substance capable of rapid Vibration, is attached, by riveting or otherwise, the small magnet or short bar of metal 61, capable of inductive action, andbf such small size and weight as not to unduly check or impede the vibrations of the diaphragm or tympan.

Though the dimensions of the small magnet (1 may vary with the size of the other parts of the telephone, I have found that a piece of iron wire No. 9, B. V. G.,from one-fourth to three-eighths of an inch long, answers admirably for the said magnet d. The piece 11 is preferably rounded oif or reduced in diameter at the point where it touches the diaphragm D to the smallest size consistent with its secure attachment thereto. The diaphragm D does not require to be attached to the case A all around its its periphery, as usual, but may rest upon the heads of three or more screws, a a, which may for convenience of adjustment have shoulders formed upon them to receive the edge of the diaphragm and insure its exactly concentric position in the case A, and

relatively to the magnet Band solenoids or helices.

Surrounding the small magnet d is a second helix, E, of insulated wire,which is wound around the wooden bobbin 0, formed in or so 'as to be one with the bobbin 0, on which is the helix 0. WV ire No. 36, B. \V. G., answers well for the helix E. The two helices O E are so wound that the current will pass through them both in the same direction, and the line-wire leading from the terminal G is divided, so as to split the currents, sending one half through each helix, and after passing through the two helices in one and the same direction the two portions of the split current enter the returnwire and pass to the terminal F. If it is desired to further reduce the resistance of the two helices, they or either of them may be wound with two or more wires, as shown in Fig. 3, the current being sent through all in the same direction. The bobbin 0 of the helix E is accurately turned and drilled at the center to receive the small magnet (i, being of such size as will just allow the magnet to reciprocate freely without touching the bobbin.

The diaphragm D is adjusted at such a distance from the pole B of the magnet 13 that the end of the small magnet (I, when the diaphragm is vibrating, shall be as close as possible to, though without coming in contact with, the pole B. The diaphragm D is held in place by the mouth or car piece A of the telephone-case, which may be screwed down upon it, so as to hold it all around, or so as to holdit in three or more places; and the concentric adjustment of the diaphragm may be effected by shifting it with the finger-nail or otherwise before finally screwing down the mouth-piece A It will be understood that, on speakinginto the mouthpiece A the diaphragm D will be caused to vibrate, and the consequent endwise movement of the small magnet d within the coils of the helix E, and in close proximity to the pole B of the main magnet, will have the eifect of greatly increasing the electrical currents transmitted to the line-wires.

If the instrument be used as a receiver, the variations in the electrical current passing through the linewire and around the helices O E will cause the piece (I to receive a rapid reciprocation endwise corresponding to the variations in the current, and thereby set the diaphragm D in action.

Fig. 2 shows the invention embodied in a telephone having a permanent or horseshoe magnet, B, when it is desired to utilize the inductive influence of both legs. B is a polepieee made fast to one of the legs by a nut, S, and surrounded by the larger helix, 0.

Thehorseshoe-magnet is attached to the telephone-ease A by one leg, and the other leg, which is situated in front of the small helix E, has a hole made in it of suflicientsize to receive the small magnet d, which is attached to the diaphragm D, and allow it to work freely through the leg of the magnet.

The magnet B may be either apermanent or an electro magnet, and the piece (Z may be a permanent magnet. I

Vhat I claim as my invention, and desire to secure by Letters Patent, is-

In an electric telephone, the combination, with the diaphragm or vibrator D, fitted with a small magnet or piece of metal, (I, capable of inductive action, and a main magnet, B, opposed to said small magnet, of the coils or helices O E, arranged concentric with such magnets, and wound, as described, so that a divided current will flow through each of the coils in one and the same direction, and act simultaneously and in precisely the same manner upon the two magnets, substantially as herein set forth.

H. B. T. STRANGWAYS.

Witnesses:

H. K. WHITE, Gno. CANTLE,

N0. 66 Chauncery Lane, London. 

